The legislation would criminalize knowingly spreading wrong information related to the time and place of elections as well as voter qualifications and registration status. The bill would also make it illegal to knowingly claim an endorsement from someone within 60 days of a federal election. Anyone who spread such misinformation would be subject to up to five years in prison and a $100,000 fine.

While dirty tricks such as fliers telling people to vote on the wrong day have a long tradition in American politics, the legislation comes amid increased attention to the spread of misinformation amid Russian interference in the 2016 presidential election.

“Misinformation campaigns intended only to suppress the vote and disenfranchise Missourians are crimes that run counter to our democratic values, and the punishment for those actions should fit the crime,” McCaskill, who is running for re-election this year, said in a statement.

Justin Levitt, a former Justice Department official charged with enforcing voting rights, said in an interview there is no federal statute that clearly prohibiting acts like telling people to vote by text message or on a Wednesday for a Tuesday election.

“That’s not currently illegal under most circumstances,” said Levitt, now a professor at Loyola Law School in Los Angeles. “Most people say that it seems crazy that it’s not illegal to tell somebody they can vote on Wednesday when actually they can’t. And I agree with that.”

There are federal laws against depriving people of civil rights, he said, but “there aren’t good, tailored targeted provisions that deal with one-off lies that cause people to not be able to exercise their right to vote.”

Most people say that it seems crazy that it’s not illegal to tell somebody they can vote on Wednesday when actually they can’t. And I agree with that.Justin Levitt, former Justice Department official

The measure would instruct the attorney general to take steps to communicate with the public to correct reported election-related misinformation and would require the attorney general after each federal election to submit a report to Congress on all allegations of deceptive practices received before that Election Day. The report would detail the race, ethnicity and language of any group targeted by a deceptive message.

“All Americans deserve the right to choose a candidate based on relevant issues and the quality of the candidates, not based on underhanded efforts to deliberately undermine the integrity of our electoral process,” Leahy said in a statement. “Reliably, these tactics seem to target minority neighborhoods and are blatant attempts to reduce turnout. Such tactics undermine and corrode our very democracy and threaten the very integrity of our electoral system.”

It can sometimes be difficult to track down the source of fake voting information, but sometimes it’s obvious, Levitt said. While it can be difficult to prove intent, when someone takes a step like using an official symbol from a state on a flyer or letterhead, that makes it clear.

While the Supreme Court has afforded significant protections to political speech, Levitt said, that does not preclude such a law, “as long as it’s really focused on logistical falsity rather than disputed campaign positions.”